The grueling sport of ultramarathon has fostered a mingling of two seemingly opposite camps: endurance jocks and potheads.

“If you can find the right level, [marijuana] takes the stress out of running,” says Avery Collins, a 22-year-old professional ultramarathoner. “And it’s a postrace, post-run remedy.”

The painkilling and nausea-reducing benefits of marijuana may make it especially tempting to ultramarathoners, who compete in races that can go far longer—and be much more withering—than the 26.2 miles of a marathon. Ultramarathon is one of the fastest-growing endurance sports; there were almost 1,300 races in the U.S. and Canada in 2014, up from 293 in 2004, according to UltraRunning Magazine.

Ultramarathons last anywhere from 30 to 200 miles, and typically crisscross mountainous terrain and rocky trails. Runners endure stomach cramps and intense pain in their muscles and joints. Competitors often quit after a sudden loss of motivation, matched with the boredom of running for upward of 24 hours straight.

“The person who is going to win an ultra is someone who can manage their pain, not puke and stay calm,” said veteran runner Jenn Shelton. “Pot does all three of those things.”

Shelton said she has trained with marijuana before, but she made a decision to never compete with the drug for ethical reasons, expressly because she believes it enhances performance.

The phenomenon isn’t easily quantified, because even in Colorado, which legalized marijuana, ultra runners declined to go on the record with their marijuana use. But marijuana is a common topic on endurance-running blogs. Often debated is whether marijuana can improve performance, particularly because of its much-heralded capacity for blocking pain. The drug is now legal for medical use in 23 states plus the District of Columbia, and a sizable portion of legal medical users cite chronic pain as a reason.

“There’s good science that suggests cannabinoids block the physical input of pain,” said Dr. Lynn Webster, founder of the Lifetree Pain Clinic in Salt Lake City. Cancer patients have also used marijuana to treat nausea from chemotherapy. For distance runners, nausea can ruin a race, preventing them from ingesting needed calories and nutrients.

Avery Collins runs on a trail near Chautauqua Park in Boulder, Colo.
Photo:
Matthew Staver for The Wall Street Journal

In a nod to the growing acceptance of marijuana as a recreational drug, the World Anti-Doping Agency in 2013 raised the allowable level of THC—the drug’s active ingredient—to an amount that would trigger positive results only in athletes consuming marijuana in competition. That essentially gave the green light to marijuana usage during training, not to mention as a stress reliever the night before a race.

In competition, a WADA spokesman said that marijuana is banned for its perceived performance enhancement, and because its use violates the “spirit of sport.”

USA Track & Field, which governs distance running in America, follows the WADA guideline. “Marijuana is on the banned list and should not be used by athletes at races,” said
Jill Geer,
a representative with USATF. “We are unequivocal in that.”

But here’s the catch. Few ultramarathons actually test for drugs, Geer said. Races must pay for drug tests, and the price tag for testing can be prohibitive for smaller events. A USADA spokesperson said that cost for drug testing depends on an event’s location, participation size, length and prominence. The Twin Cities Marathon, for example, spent $3,500 to have USADA conduct six tests at its 2014 event.

In many other sports, a handful of athletes over the years have acknowledged using pot as a painkiller and relaxing agent. Canadian snowboarder Ross Rebagliati—who briefly lost and then regained his 1998 Olympic gold medal after testing positive for pot—admitted that he regularly smoked marijuana during his professional career. Mixed martial arts fighter Nick Diaz is unapologetic for his use of medical marijuana; a positive pot test earned him a yearlong ban in 2012. Retired NFL wide receiver
Nate Jackson
detailed his marijuana use in a 2013 book, saying he regularly smoked pot to numb his various sports injuries.

Pot’s original inclusion on the Olympic banned list had more to do with politics and ethics than its perceived performance enhancement, said veteran drug tester Don Catlin, who founded the UCLA Olympic Analytic Laboratory. “You can find some people who argue that marijuana has performance-enhancing characteristics. They are few and far between,” he said. “It’s seen more as a drug of abuse than as a drug of performance enhancement.”

The running movement has long been a haven for hippies, and ultramarathons in particular feature an above-average number of ponytailed graybeards.

“There’s a great degree of rugged individualism in every ultramarathoner,” says ultramarathoner Jason “Ras” Vaughn, who operates the popular blog UltraPedestrian.com. “My impression is that the runners who use [marijuana] are people who already smoked it, who now happen to be ultra runners.”

Shelton, the ultra runner who doesn’t use pot during races, said the ultramarathon community generally is aware of those who do so. Pot, she said, is just one of the numerous painkillers that athletes take during the grueling races. It isn’t uncommon for athletes to pop multiple Advil or Tylenol during a 100-mile race.

Collins runs on a trail.
Photo:
Matthew Staver for The Wall Street Journal

Unusually candid about his marijuana usage is Collins. During a typical week at his home in Steamboat Springs, Colo., Collins runs approximately 150 miles and consumes marijuana four or five times. He doesn’t smoke the plant; instead he eats marijuana-laced food, inhales it as water vapor and rubs a marijuana-infused balm onto his legs.

Collins is no back-of-the-pack stoner. In 2014, his first year as a full-time professional runner, he won five ultramarathons. His third-place finish at the Fat Dog 120, a well-known 120-mile race in British Columbia, was the top American result.

Collins says he doesn’t ingest the plant during competitions, though he says he has never been tested. He does train with the drug, on occasion. He says the marijuana balm numbs his leg muscles, and small doses of the plant keep his mind occupied during longer runs, he says. Collins says the miles and hours seem to tick off faster when he is running high.

After a race, Collins eats marijuana candies or cookies to lower his heart rate and relax his muscles.

“You’re running for 17 to 20 hours straight, and when you stop, sometimes your legs and your brain don’t just stop,” Collins said. “Sometimes [pot] is the only way I can fall asleep after racing.”

Collins recently landed a small cash sponsorship with a Colorado company that consults with marijuana growers and sellers. For 2015, he will wear the company’s pot-leaf logo on his jersey and promote the company on social media.

Even as he promotes a marijuana-related sponsor, however, Collins concedes that his latest training strategy—involving shorter, faster, more-focused sessions—doesn’t fit well with running high. So he is doing a lot less of that.